With the continuous development of display technologies, dimensions of displays change with each passing day. To meet portability of electronic devices, the demand for display screens with smaller dimensions is ever-increasing.
Meanwhile, users put forward higher requirements for the display quality of the display screens. For example, the users are apt to prefer display screens with high Pixels per Inch (PPI) to improve display accuracy, resolution, and coherence.
An organic light emitting diode (OLED) display is more widely used in various portable electronic devices because of its slim and flexible shape, light weight, and power saving features, etc.
The OLED display generally includes an OLED array (namely, a pixel array), driving circuits (namely, pixel circuits) configured to provide driving current for each OLED in the array, and scanning circuits configured to provide drive signals for each pixel circuit.
However, in existing OLED displays, generally, pixel circuits only compensate threshold voltages (Vth) of driving transistors, but no consideration is given to problems of carrier mobility of the driving transistors and aging of light emitting components with the accumulation of service time. For example, as time goes on, when current flows through the light emitting components, forward voltage drop (minimum forward voltage at which the light emitting components can be turned on under assigned forward current) of the light emitting components increases, and the light emitting components generally connect sources/drains of the driving transistors. Therefore, the source to drain voltage difference of the driving transistor diminishes, which may reduce the light emitting current flowing through the light emitting components. However, a plurality of light emitting components and driving transistors are present in the OLED displays, aging degree of each light emitting component and variation degree of the carrier mobility of the driving transistors are different, as a result these light emitting components become different in display brightness even though the same display signal is provided to each pixel circuit, and further cause deterioration of display uniformity of the OLED displays.